/Engine/Source/Runtime/Engine/Public/MaterialShared.h
Get a combined hash of all referenced Texture2D's underlying RHI textures, going through TextureReferences. Can be used to tell if any texture has gone through texture streaming mip changes recently.
uint32 GetReferencedTexture2DRHIHash ( const [FMaterialRenderContext](API\Runtime\Engine\FMaterialRenderContext) & MaterialRenderContext ) const